Delta IV Heavy blasts off with classified NROL-15 Payload

June 29, 2012UPDATED

UPDATE: 21:00 GMTUnited Launch Alliance has declared Friday's Delta IV Rocket Launch with the classified NROL-15 Payload for the US National Reconnaissance Office a Success. "Today’s successful launch of the NROL-15 mission is the third of four launches for the NRO this year and the second EELV launch for the NRO in just nine days," said Jim Sponnick, ULA vice president, Mission Operations. "We congratulate the combined NRO, U.S. Air Force and ULA team along with our mission partners for their continued focus on mission success as we deliver the critical capabilities to support the soldiers, sailors, airmen and Marines."

Delta IV Heavy *File Image* - Photo: United Launch Alliance

A United Launch Alliance Delta IV Heavy Launch Vehicle blasted off from Space Launch Complex 37 at Cape Canaveral Air Force Station at 13:15 GMT on Friday, June 29, 2012 on a classified mission to deliver the NROL-15 Payload Orbit for the US National Reconnaissance Office. The Countdown was rather eventful with three unplanned Holds in the Terminal Countdown Sequence causing a launch delay of more than three hours. Liftoff was normal and the first portion of the vehicle's ascent went smoothly before the launcher headed into the nominal News Blackout that comes with each classified National Reconnaissance Office Mission.Final Launch Preparations got underway late on Thursday, local time, when the large Mobile Service Structure was retracted from the Delta IV Heavy – exposing the huge launcher standing tall at the Launch Pad. The MST was used during Launch Vehicle Integration and Checkouts to provide access to the Delta IV. Also, it protected the vehicle from the harsh weather conditions that were observed over the past several days. The MST is 100 meters tall and it can be moved to safe distance to the Launch Pad to prevent it from being damaged during blastoff. Mobile Service Structure Retraction took place at around Midnight GMT to set the stage for countdown operations. Technicians performed final Launch Pad and Vehicle close-outs as part of nominal pre-countdown operations. The Launch Team reported to console just after midnight local time – 4am GMT. After the launch team had arrived, a weather briefing was given to the team before clocks started ticking. Clocks started ticking at T-5:15 at 4:43 GMT and countdown operations began with Launch Vehicle Power up and subsystem activation. The GO/No GO Poll for Fueling was performed and the team decided that Weather Conditions were good enough to make a launch attempt as Meteorologists predicted a 90% Chance of favorable Weather during the launch window. The complex Delta IV Tanking Process started at T-4 Hours and 50 Minutes when LOX Loading of the three Common Booster Cores began. The fueling process went through the nominal slow fill, fast fill and topping phases before entering replenish. Common Booster Core Liquid Hydrogen Loading got underway on time at T-3 Hours and 40 Minutes and also involved the slow fill, fast fill and topping modes.

Each CBC was loaded with 200,00 Kilograms of cryogenic propellants.As the countdown continued on track, the Delta IV Launcher underwent extensive systems checks. The Guidance System was activated and tested and the launch team received several weather briefings as clocks continued to tick down. Upper Stage fueling started at T-2 Hours 55 Minutes with LOX Loading followed by LH2 Tanking 15 Minutes later – also going through the three different tanking modes. The second stage holds a total of 27,220 Kilograms of Propellants at Liftoff. At T-1 Hour and 25 Minutes, the Rocket completed Communications and Telemetry Checks to make sure that there would be a stable data stream coming form the vehicle during powered flight. At T-50 Minutes, the three Common Booster Cores completed RS-68A Engine Spin Start Pressurization and the Main Engines were put through a Gimbal Steering Profile in order to make sure all powerplants were ready for the flight. As the countdown progressed, more vehicle tests were made and meteorologists continued to watch the weather and provided updates to the launch team. Just prior the Built-In Hold, the Launch Pad’s Ordnances were armed in preparation for Blastoff. At T-4 Minutes, the Countdown entered its 15-minute built-in hold giving the launch team a chance to take care of any open items, address any technical issues and perform final vehicle checks. During the hold, the Payload was transferred to internal power and configured for launch. Also, the launch team made the final GO/No GO Poll before pressing into the Terminal Countdown Sequence. As soon as coming out of the Hold, the launch vehicle switched to internal power supply and the Safe and Arm Devices were armed for launch. At T-3 Minutes and 42 Seconds, the Countdown Control Script detected a problem and stopped the Automated Sequence immediately. The Launch team responded by starting Safing and Recycle Operations and the Launcher was placed in a secure Configuration for an extended Recycle as teams needed more time to address the issue. Air Force Range controllers were asked to extend the Range Clear Time to make sure a second Launch Attempt could be made after the issue was investigated and resolved. The Problem was tied to an incorrect Trigger detecting a spike in Battery Current when the vehicle switched internal power. Performance was determined to be nominal and the Red-Line Limit was disabled since teams were able to monitor the Electrical Subsystem Current via a different sensor. All Stations agreed with the plan and teams re-set the countdown. Clocks started ticking again at 10:46 GMT at T-4 Minutes resuming with Transfer to Internal. A Propellant System Issue stopped the count at T-3 minutes and 17 Seconds. Computers detected an off-nominal parameter related to the Upper Stage Liquid Oxygen Fill & Drain Valve and stopped the Automated Countdown Sequence when detecting that the valve failed to close within the specified 10 Seconds (Red-Line Limit). The Vehicle was safed and the launch team started discussing the problem. The issue was evaluated by the launch team taking advantage of a long launch window. Its exact duration was not disclosed to the public. The root cause of the problem was identified some time later as teams worked the issue. The LOX Topping Script and the the LOX Securing Script were running simultaneously which caused the T&D Valve to re-open as commanded by the falsely activated Topping Script. A decision was made to manually terminate the Topping Script to make sure the correct closure time of the valve is achieved. This modified T-4 Minute Countdown Sequence was resumed and the manual override was executed as expected with the launcher going through the nominal procedures to go to internal power and enable the Launch Sequencer.Shortly after the previous Hold Point was passed, another unplanned hold was called at T-3:09. After the vehicle was secured, teams looked at a Fuel Fill and Drain Valve on one of the Common Booster Cores that did not close properly due to back pressure which is a well understood problem. Teams examined the situation and re-set the countdown for T-0 at 13:15 GMT after making cycles of all valves aboard the Launcher except the previously cycled Upper Stage F&D Valve). The Count resumed as planned and clocks eventually completed the first minute of the Terminal Countdown.3 Minutes before Liftoff, the three Common Booster Cores finished Liquid Oxygen and Liquid Hydrogen securing and all CBC Tanks were pressurized for flight while flight computers and launch team members closely monitored all launch vehicle parameters tracking the countdown process. Shortly thereafter, the Cryogenic Upper Stage started securing its LOX and LH2. Range Controllers reported that the Range was clear for launch and the Hydraulic System was checked one final time to verify the system was at proper flight pressure. 50 seconds prior to Blastoff, the tanks of the Upper Stage reached Flight Pressure. The Launch System was enabled at T-45 seconds. 14 seconds before T-0, the Radially Outward Firing Initiators (ROFIs) ignited beneath the three Main Engines to burn residual Hydrogen. At T-8.5 seconds, the Terminal Countdown Sequencer assumed control over the countdown managing the final events and monitoring all launch vehicle parameters. Three seconds later, the Main Fuel Valves of the RS-68A Engines opened allowing Hydrogen to flow through the engine to start the Ignition Sequence. A large red flame erupted from the Launch Table as Hydrogen was burned before the Main Oxidizer Valves were opened at T-2 seconds.

This launch of the Delta IV Heavy marked the premier flight of the RS-68A Engine which is a more powerful version of the RS-68 Engines that were and are currently used on Delta IV launchers. RS-68A features a 13% performance increase over the conventional RS-68 raising the Geostationary Transfer Orbit Payload Capability of the Delta IV Heavy to 14,560 Kilograms. RS-68 and RS-68A Engines are built by Pratt & Whitney Rocketdyne. The engine is a gas generator cycle engine with two independent turbopumps feeding a combustion chamber that is using a channel-wall design. Inner and outer skins brazed to middle separators form cooling channels as part of a simple engine design. The engine nozzle has a lining that burns away during the main engine burn to provide additional cooling. The RS-68A will become the Main Engine of the Common Booster Core of all Delta IV Vehicles starting in 2015 since existing RS-68 powerplants will be used on upcoming missions. RS-68A was specially developed for this flight because the classified payload required an increase in Launch Vehicle performance for reasons that have not been disclosed due to the nature of the mission.The three RS-68A engines soared to life as they were spinning up to Flight Speed. Computers monitored the three engines and confirmed a nominal start-up and initial performance up to the Full Thrust Level. At T-0.04 seconds, launch commit occurred and 12 hold-down bolts were pyrotechnically separated – allowing the 733,000-Kilogram Rocket to blast off.At blastoff, each of the three RS-68A Main Engines provides 3,140 Kilonewtons of thrust as they operate at 108.5% of rated performance. After completing its initial ascent, the launcher makes a pitch and yaw maneuver to align itself with its pre-planned launch trajectory. 50 Seconds after lifting off from SLC-37, the Center Common Booster Core is throttled back to 56.5% Thrust to save propellants. The other two CBCs continued to perform at Full Thrust. The vehicle encountered Maximum Dynamic Pressure at about T+81 seconds and the launcher passed Mach 1 just a few seconds later. Just before being jettisoned at T+4 Minutes and 9 Seconds, the two strap-on boosters throttled down and eventually performed Main Engine Cutoff.

Photo: United Launch Alliance

Photo: United Launch Alliance

The Center Booster throttled back up to 108.5% and continued to power the vehicle for another 88 seconds before shutting down and separating from the Upper Stage. A few seconds after Staging, the RL-10B-2 Engine of the second stage ignited and began its first burn. Shortly after ignition, the protective Payload Fairing separated from the vehicle as thermal and aerodynamic loads were within limits at that time in the flight for the Payload to be exposed. At that point, the Vehicle flew into the customary News Blackout of National Reconnaissance Office Missions. Mission Events will not be announced in real time and Launch Success will be announced several hours after the actual event. Well before launch, as soon it was announced that the NROL-15 Payload would fly with the RS-68A Engine, speculation broke out among Space Analysts and Satellite Trackers regarding the nature of this mission's payload and the Flight Profile of the Delta IV Heavy Launcher. The utilization of the RS-68A Engine the Payload must be a heavy satellite needing an increased amount of Launch Vehicle Performance or implying that the launcher will climb all the way to Geosynchronous Orbit - or that the ascent profile includes a dogleg trajectory taking the vehicle to a higher inclination orbit. What is known is that the NROL-15 has driven the improvements of the RS-68 Engine for this mission’s customer, the NRO.The Launch Azimuth and Drop Zones of the Strap-On Boosters and the Center CBC suggest that the Delta IV heavy was targeting a Geosynchronous Orbit (inclined Geostationary Orbit) or a Geosynchronous Transfer Orbit. For a Mission directly to GSO or GEO, the Delta IV Upper Stage would make three Burns placing the Spacecraft in a 35,780-Kilometer Orbit. A mission to a GSO or GEO Transfer Orbit would most likely require two Upper Stage Burns placing the Payload in an elliptical Orbit of about 200 by 35,800 Kilometers. The Upper Stage of the Delta IV Heavy Launcher will not make a destructive re-entry after completing its mission since no NOTAM (Notice to Airmen) was issued specifying the Entry Zone. This suggests that the Upper Stage will be left in a Graveyard Orbit or a Solar Orbit for disposal.

Image: NRO

Well known Satellite Tracker and Space Analyst Ted Molczan (www.satobs.org) has published two theories, both based on the Satellite being the third Misty Spacecraft - which is a valid theory because it is a known fact that a Misty Satellite was planned to be launched in 2009 (as of 2004) with evidence suggesting that the launch was postponed due to the lack of ascent performance caused by RS-68A development needing more time. Two Misty Satellites have been launched in the 1990s. One by Space Shuttle Atlantis on March 1, 1990 and the second one on May 22, 1999 by a Titan IV Rocket. The Misty Project is heavily classified and there are no confirmed details. Misty Satellites are believed to be photo reconnaissance vehicles operating in a Low Earth Orbit. Misty is reported to employ an optical and radar stealth technology making it difficult to be detected by any tracking system on the ground. Patent US5345238 is describing a Satellite Signature Suppression Shield that is most likely being utilized on Misty Spacecraft. The Patent includes a brief description of the System: "The shield is conical-shaped and made from a thin synthetic polymer film material coated with a radiation reflecting material, such as gold or aluminum. At least one subliming agent is contained within the shield to inflate the shield when exposed to heat. An ultraviolet curable slurry coats the inner walls of the shield and permanently hardens the shield upon exposure to ultraviolet radiation from a self-contained source." Misty Satellites are built by Lockheed Martin Space Systems and are known to be heavy Payloads of at least 19,000 Kilograms. As Misty is a Low Earth Orbit Satellite and does not target a GEO or GSO, Molczan has developed a theory on two possible mission profiles: One with Payload Separation in Low Earth Parking Orbit and subsequent maneuvering of the Payload into a 35-degree, 700 Kilometer Orbit and the Delta IV Upper Stage deploying a decoy of about 1,500 Kilograms masking a Signal Intelligence Gathering Satellite in Geosynchronous Orbit (SIGINT). His second scenario is a Payload Deployment in Low Earth Orbit followed by Disposal of the Upper Stage in Solar Orbit. "If nothing new shows up in GEO, then the no-decoy concept will look more attractive. If the second stage and a bright payload show up in GEO, then we will need to decide whether it's an actual SIGINT or a decoy. A high-fidelity decoy may not be immediately distinguishable from an actual SIGINT payload, in which case, I would be left with only my suspicions and proof of nothing," Ted Molczan writes.

In case of this Launch actually being a Misty Low Earth Orbit Satellite, the extra performance of the RS-68A engine would be used for an inclination increase instead of using its extra power to go into a high orbit. With a higher inclination, optical satellites can cover a bigger portion of Earth's Surface. Whether Molczan's Theory is correct will be hard to verify since a Misty Satellite is impossible to track for any Satellite Observers. NROL-15 is likely to remain a mystery until declassification which is not going to occur in the near future.

Final Launch Preparations underway ahead of Overnight Countdown

June 28, 2012

Teams at the Cape Canaveral Air Force Station have started the final preparations for the Launch of a Delta IV Heavy carrying the classified NROL-15 Payload for the US National Reconnaissance Office. T-0 is planned for 10:13 GMT on Friday. Launch Weather is 90% GO. Technicians are performing final Launch Pad and Vehicle close-outs as part of nominal pre-countdown operations. The large Mobile Service Tower will be retracted late on Thursday, local time, and placed in its Launch Position at a safe Distance to the Launch Pad. The Structure was used to assemble and protect the launcher during its 3-month stay at Space Launch Complex 37. Before Countdown Clocks start ticking 5 Hours and 30 Minutes prior to Blastoff, technicians begin closing out the Service Structure and Launch Pad. After securing is complete, the area will be cleared in advance of the countdown. Clocks will start ticking at T-5:15 at 4:43 GMT and countdown operations will begin with Launch Vehicle Power up and a weather briefing for the launch team. Should there be no chance of favorable weather, the countdown will be stopped prior to fueling. If there is a good chance of cooperative weather, the launch team will press into fueling and proceed until T-4 Minutes when a planned built-in hold begins. The complex Delta IV Tanking Process will begin at T-4 Hours and 50 Minutes when LOX Loading of the three Common Booster Cores begins. The fueling process will go through the nominal slow fill, fast fill and topping phases. Common Booster Core Liquid Hydrogen Loading begins at T-3 Hours and 40 Minutes and also involves the slow fill, fast fill and topping modes. Each CBC will be loaded with 200,00 Kilograms of cryogenic propellants. As the countdown continues, the Delta IV Launcher will undergo extensive systems checks. The Guidance System will be activated and tested and the launch team will receive several weather briefings as clock continue ticking. Upper Stage fueling will begin at T-2 Hours 55 Minutes with LOX Loading followed by LH2 Tanking 15 Minutes later – also going through the three different tanking modes. The second stage holds a total of 27,220 Kilograms of Propellants at Liftoff.

Photo: United Launch Alliance

At T-1 Hour and 25 Minutes, the Rocket undergoes Communications and Telemetry Checks to make sure that there will be a stable data stream coming form the vehicle during powered flight. At T-50 Minutes, the three Common Booster Cores complete RS-68 Engine Spin Start Pressurization and the three RS-68A Main Engines will be put through a Gimbal Steering Profile making sure all powerplants are ready for the flight. As clocks continue to tick down, more vehicle tests will be made and meteorologists will continue to watch the weather and provides updates to the launch team. Just prior the Built-In Hold, the Launch Pad’s Ordnances will be armed in preparation for Blastoff. At T-4 Minutes, the Countdown enters a 15-minute built-in hold that can be extended if required – for instance due to unfavorable weather conditions or technical issues that need to be addressed. During the hols, the Payload will be transferred to internal power and configured for launch. Also, the launch team will perform the final GO/No GO Poll before pressing into the Terminal Countdown Sequence. As soon as coming out of the Hold, the launch vehicle switches to internal power supply and the Safe and Arm Devices are armed for launch. 3 Minutes before Liftoff, the three Common Booster Cores will have completed Liquid Oxygen and Liquid Hydrogen securing and all CBC Tanks will be pressurized for flight. Shortly thereafter, the Cryogenic Upper Stage will begin securing its LOX and LH2. The Launch Team will make one more vehicle status check verifying that the Hydraulic System is operating nominally and Range Controllers will report a Range Clear For Launch. 50 Seconds prior to Blastoff, the tanks of the Upper Stage will be at Flight Pressure. The Launch System is enabled at T-45 Seconds. 14 Seconds before T-0, the Radially Outward Firing Initiators (ROFIs) will be ignited beneath the three Main Engines to burn residual Hydrogen. At T-8.5 seconds, the Terminal Countdown Sequencer assumes control over the countdown managing the final events and monitoring all launch vehicle parameters. Three seconds later, the Main Fuel Valve of the RS-68A Engines are opened allowing Hydrogen to flow through the engine to start the Ignition Sequence. A large red flame will erupt from the Launch Table as Hydrogen burns before the Main Oxidizer Valves are opened at T-2 seconds. The three RS-68A engines will then soar to life as they spin up to Flight Speed. Computers will be monitoring the three engines and confirm a nominal start-up and initial performance. A T-0.04 seconds, launch commit occurs and 12 hold-down bolts are pyrotechnically separated – allowing the 733,000-Kilogram to lift off.

Photo: United Launch Alliance

At blastoff, each of the three RS-68A Main Engines provides 3,140 Kilonewtons of thrust as they operate at 108% of rated performance. After completing its initial ascent, the launcher makes a pitch and yaw maneuver to align itself with its pre-planned launch trajectory. 50 Seconds after lifting off from SLC-37, the Center Common Booster Core is throttled back to 56.5% Thrust to save propellants. The other two CBCs continued to perform at Full Thrust. The vehicle encounters Maximum Dynamic Pressure at about T+81 seconds and the launcher passes Mach 1 just a few seconds later. Just before being jettisoned at T+4 Minutes and 9 Seconds, the two strap-on boosters throttle down and eventually perform Main Engine Cutoff. The Center Booster throttles up to 108% and continues to power the vehicle for another 88 seconds before shutting down and separating from the Upper Stage. A few seconds after Staging, the RL-10B-2 Engine of the second stage ignites and begins its first burn. Shortly after ignition, the protective Payload Fairing separates from the vehicle as thermal and aerodynamic loads are within limits at that point in the flight for the Payload to be exposed.

At that point, the Vehicle will fly into the customary News Blackout of National Reconnaissance Office Missions. Mission Events will not be announced in real time and Launch Success will be announced several hours after the actual event. United Launch Alliance will provide a Webcast of the Launch and initial portion of the ascent up to the point of PLF Separation.The ULA Webcast is availablehere.Live Countdown and Launch Updates will be available via the Spaceflight101 Twitter Feed. Photo Gallery: Delta IV poised for Launch

Delta IV Heavy Launch delayed due to Tropical Storm

June 26, 2012

*File Image* - Photo: United Launch Alliance

_A Delta IV
Heavy Launch Vehicle has passed its Flight Readiness Review – clearing the way
for an launch attempt later this week from Space Launch
Complex 37 at Cape Canaveral Air Force Station. The Launch has been rescheduled for Friday, June 29, 2012 with T-0 occurring at 10:13 GMT.Mission
Managers met on Tuesday to discuss all Systems required for the launch attempt,
those of the Delta Rocket and the Ground Support Equipment at the Launch
Complex as well as the network of downrange communications systems. A decision
to press into final launch preparations was made, but later on Tuesday, United Launch Alliance announced that the launch is being delayed 24 hours due to an unfavorable weather forecast.Conditions on Friday are expected to be slightly better than during Thursday's Launch WindowMeteorologists are currently watching tropical storm Debby that is expected to bring clouds, high winds and
rain to the Space Coast on Thursday and Friday. Primary concerns are
violations of the Cumulus and Anvil Cloud Rules as well as high ground-winds,
thick clouds and showers. Whether a launch attempt will be made or not will be
decided prior to fueling when the first Countdown Weather Briefing takes place.
Should there be no chance of favorable weather, the countdown will be stopped
prior to fueling and the launch will be delayed further. If there is a small chance of cooperative weather, the launch
team will press into fueling and proceed until T-4 Minutes when a planned
built-in hold begins. Should weather conditions not clear up at some point in
the launch window, the countdown will be stopped and the Delta IV will undergo safing
and de-tanking.
Launch Operations are set to kick off late on Thursday, local time, with the Retraction of the Service Structure that was placed around
the Delta IV Vehicle since it arrived at the Launch Complex in April and also protects the vehicle from the rough weather conditions expected for the coming days. Countdown
clocks will pick up at the T-5:15-Minute Mark (L-5:30) at 4:43 GMT. A complete
Delta IV Countdown Timeline is available here. For more information on the Delta
IV Heavy Launcher, visit ourLaunch Vehicle Overview.

Launch Preparations on Track, Weather Outlook not optimistic

June 25, 2012

Image: United Launch Alliance

_Launch Week
is underway at the Cape Canaveral Air Force Station Florida, where a Delta IV
Heavy Rocket is being prepared for blastoff on Thursday, June 28, 2012 from Space Launch Complex 37.With the
secret NROL-15 Payload mounted atop the large launch vehicle, integrated
testing has been completed and the stack was put through countdown and flight
simulations. During pre-flight inspections, technicians found a faulty vent
relief valve on the Center Common Booster Core of the Delta IV Launcher. This
valve was replaced over the weekend and tests were performed to ensure the new
component is working as expected. Officials have also announced the targeted
liftoff time of the classified NROL-15 Payload. Liftoff is scheduled for
Thursday at 10:16 GMT, but the duration of the day’s launch window has not been
published. Earlier, Officials said that the launch would occur at some point
between 9:30 and 14:30 GMT on June 28.Meteorologists
are not optimistic about Thursday’s Launch Opportunity issuing a 30% chance of
favorable weather. With Tropical Storm Debby, currently located over the Gulf of Mexico,
there is a high potential for clouds and rain along the Florida Space Coast.
For backup launch slots on Friday and Saturday, the probability of cooperative
weather increases to 40% and 70%, respectively. All these forecast models come with
the uncertainty on the tropical storm's path and forecasts will become more
refined as time progresses towards launch.This launch will be the
premiere of the RS-68A Engine increasing the ascent performance of the
launcher. RS-68A is based on the RS-68 Engine that has been used on all
previous Delta IV Missions. RS-68 and RS-68A Engines are built by Pratt &
Whitney Rocketdyne. Using the improved RS-68A Version, the payload capability
of the Delta IV Heavy is boosted by 13%. Payloads of up to 14,560 Kilograms can
be placed in Geostationary Transfer Orbit by the vehicle as each of the three
RS-68A Engines of the main Common Booster Core and the two strap-on CBCs of the
launcher provides a liftoff thrust of 3,140 Kilonewtons. It is the largest Hydrogen-Fueled
Engine of the world.

_The engine is a gas generator cycle engine with two independent turbopumps feeding a combustion chamber that is using a channel-wall design. Inner and outer skins brazed to middle separators form
cooling channels as part of a simple engine design. The engine nozzle has a
lining that burns away during the main engine burn to provide additional
cooling. More information about the Delta IV Launch Systems can be found here.
Wild speculation about the
NROL-15 Payload had been underway since it was announced that its launch
vehicle would be using the improved RS-68A engines – suggesting that the
Payload must be a heavy satellite needing an increased amount of Launch Vehicle
Performance or implying that the launcher will climb all the way to
Geosynchronous Orbit. What is known is that the NROL-15 has driven the
improvements of the RS-68 Engine for this mission’s customer, the NRO.
Currently, space analysts do not have an educated guess on the NROL-15 Payload.
Should NOTAMS for the re-entry/impact zone of the Upper Stage of the Delta IV Rocket be issued, some
information on the flight profile could be obtained. Satellite trackers around the world will be watching the sky after the launch to find NROL-15 and possibly reveal its identity.

Delta IV Heavy Launcher ready for Classified NRO Flight

June 14, 2012

_Setting the Stage for the second classified
launch for the US National Reconnaissance Office in June, a Delta IV Heavy
operated by United Launch Alliance is undergoing final Launch Preparations at
Space Launch Complex 37 at the Cape Canaveral Air Force Station. The Delta IV
is set to launch on June 28 during a 5-hour launch period starting at 9:30 GMT
beginning its ascent mission to deliver the secret NROL-15 payload to its
classified orbit. As per usual procedures with NRO Launches, the nature of the
payload, details on the ascent profile and the targeted orbit remain secrets.
Also, the exact length of the launch window is not being disclosed. The launch campaign began several months ago
with the delivery of the components of the Delta IV Heavy Launcher. Initial
integration of the rocket, including mating of the three Common Booster Cores
and installation of the 5-meter cryogenic upper stage using a precision laser
alignment system, had been completed inside the Horizontal Integration Facility
of SLC-37. After the integration process was complete, the stack was rolled out
to the Launch Pad and its Service Structure on April 4, 2012. Once at the pad,
the stack was placed in its vertical position atop the launch platform. Vehicle
checkouts and testing was completed and the Rocket is now ready for Payload
Integration that will complete the lengthy launch build-up for the Delta IV
Heavy.

Patch: NRO

_This launch will be the premiere of the RS-68A
Engine increasing the ascent performance of the launcher. RS-68A is based on the
RS-68 Engine that has been used on all previous Delta IV Missions. RS-68 and
RS-68A Engines are built by Pratt & Whitney Rocketdyne. Using the improved
RS-68A Version, the payload capability of the Delta IV Heavy is boosted by 13%.
Payloads of up to 14,560 Kilograms can be placed in Geostationary Transfer
Orbit by the vehicle as each of the three RS-68A Engines of the main Common
Booster Core and the two strap-on CBCs of the launcher provides a liftoff
thrust of 3,140 Kilonewtons. It is the largest Hydrogen-Fueled
Engine of the world. The engine is a gas generator cycle engine with two
independent turbopumps feeding a combustion chamber that is using a
channel-wall design. Inner and outer skins brazed to middle separators form
cooling channels as part of a simple engine design. The engine nozzle has a
lining that burns away during the main engine burn to provide additional
cooling. More information about the Delta IV Launch Systems can be found here.
Wild speculation about the NROL-15 Payload had been underway since it
was announced that its launch vehicle would be using the improved RS-68A
engines – suggesting that the Payload must be a heavy satellite needing an
increased amount of Launch Vehicle Performance or implying that the launcher
will climb all the way to Geosynchronous Orbit. What is known is that the
NROL-15 has driven the improvements of the RS-68 Engine for this mission’s
customer, the NRO. It is expected that educated guesses on this flight’s
payload will be made after the Notices to Airmen are published leading up to
Launch Day.

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